Tube reducing machine



Dec. 9, 1941. w. E. AMBERG TUBE REDUCING MACHINE Filed Nov. 5, 1958 5 Sheets-Sheet 1 Dec. 9, 1941. w. E. AMBERG TUBE REDUCING MACHINE Filed Nov. 5, 1938 5 Sheets-Sheet 2 IN VENTOR.

Wcd

ATTORNEY.

Dec. 9, 1941. w. E. AMBERG 2,265,713

TUBE REDUCING MACHINE Filed Nov. 5, 1938 5 Shee ts-Sheet s INVENTOR.

BYWW

ATTORNEY.

5 Sheets-Sheet 4 w. E. AMBERG TUBE REDUCING MACHINE Filed Nov. 5, 1958 Dec. 9, 1941.

v INVENTOR. Zia/"15. [Zr/2b ATTORNEY.

Dec. 9, 1941. w. E. AMBERG 2,265,713

TUBE REDUCING MACHINE Filed NOV. 5, 1938 5 Sheets-Sheet 5 J0 60 [@15.

L1? I 'T I INVENTOR. wagjfi. (Zmefg,

ATTORNEY.

Patented Dec. 9, 1941 TUBE REDUCING MACHINE Walter E. Amberg, Chicago, Ill., assignor, by

mesne assignments, to Metal Tube Shaping Corporation, -Elkhart,,lnd., a corporation of Indiana Application November 5, 1938, Serial No. 239,168

Claims.

This invention relates to machines and processes for changing the outer contour or profile of metal tubing or reducing the wall thickness of tubular products. Also the machine and process contemplate reducing the wall thickness of a tubular product while simultaneously changing its profile or contour. Thus, a taper may be imparted to a tube and simultaneously throughout,

the taper, or at certain points thereof, the wall thickness may be reduced. 1

Today the tapering of metal tubes is commonly brought about by means of a swaging operation in which a plurality of oppositely disposed and oppositely grooved segmental dies are employed. These members are rocked back and forth with a tubular product between them whereupon the contour of the grooves is imparted to the tube. In this fashion it is possible to taper a tube, but by virtue of the nature of the dies employed the process is, as a practical matter, limited to short sections of tubing and is comparatively expensive. Attempts have been made to taper tubing by means of the common cross roll machines, but these have proved abortive because of the tendv ency of the rolls to expand and fracture the metal.

With the foregoing desiderata in view, the present invention has for an object thereof the provision of an improved machine and method for altering economically and expeditiously the. contour or profile of relatively long sections of tubing. A feature of the invention which lends itself to the accomplishment of this object resides in the provision of what will hereinafter be termed a ring-roll for bringing about the desired change in shape. This roll comprises an annular die through the central opening of which the tube is fed, the opening in the die being larger than the outer diameter of the tube. The die is rotated at a-high rate of speed and as the tube is moved lengthwise through the central opening, the ring-roll is automatically moved toward or away from the tube to impart to the latter the desired configuration.

Additionally, as heretofore pointed out, an object of the invention consists in adapting a ringroll of the type described to the task of reducing the wall thickness of a tubular product, either simultaneously with the contour-changing operation or as a'separate and independent operation. A feature of the invention which contributes to the accomplishment of this object resides in the provision of an arbor or mandrel positioned within the hollow interior of the tube in such a manner that it cooperates with the ringroll in effecting the wall reducing operation.

From a somewhat different aspect, an important feature of the invention resides in applying to a tube a'deformative pressure by means of a tool so positioned as to displace the tube wall inwardly while imparting relative rotation between the tube and the tool, and in reinforcing the tube immediately adjacent the section ,under-' going deformation by means of a supporting bearing. By means of such an arrangement the metal of the tube is caused to flow inwardly adjacent the supporting bearing in the form of a low pitched spirally extending shoulder. Thereafter, as the tube and the tool are moved relatively to one another to cause the tool to pro-- gress lengthwise of the rotating tube, the tube is advanced slowly in order to prevent appreciable spiral grooving of the tube by causing each portion thereof to be repeatedly subjected to the pressure of the forming tool.

The invention has for still another object thereof the provision of a new and improved machine assembly of the type mentioned. Various features of the machine design lend themselves to the accomplishment of this object. For example, one feature will be found to reside in mounting the ring-roll in a swinging head and in arranging various driving or driven elements to pivot simultaneously about a single axis in order that the position of the ring-roll relative to the tube may be changed without in any wise affecting the rotation of the roll or the operation of any of the parts associated therewith.

Other objects and features of the invention will become apparent from a reading of the foltion, showing a somewhat modified version of the machine shown in Figure 1;

Figure 8 is a detailed view in section of a device capable of pushing a tube through the machine;

Figure 9 is an end view, partly in section, of the machine illustrated in Figure 1, showing the manner of mounting and driving the ring-roll;

Figure 10 is a detailed view illustrating the mechanismfor reversing the direction of travel of the tube feeding mechanism;

Figure 11 is a view in section of the driving mechanism for the ring-roll; and

Figures 12 to 18, inclusive, illustrate somewhat schematically various types of operations that the machine is capable of performing.

Generally speaking, the machine illustrated and describedherein comprises, first, a base or frame upon which the working parts are mounted; second, a swinging head surmounted on the base within which head the ring-roll is rotatably mounted; third, means for controlling the swinging movement of the head; and fourth, means for imparting feeding motion to the tube being operated upon. In the event the machine is em-' ployed for reducing the wall thickness an arbor or mandrel is employed and the machine will.

'or bearing, associated with the roll are mounted for rotary motion. The ring-roll lill is, as previously pointed out, secured within the annular housing member 46 which is formed with gear teeth that are driven by the gear 44. In order to afford proper support to the annular housing member, ball bearings and races 56, shown in Figures9 and 11, are providedand are in. turn then include means for imparting motion to the arbor as well.

Turning now to Figures 1 and 9 of the drawings, the reference numeral l0 indicates the base or frame of the machine upon which are mounted the various devices and instrumentalities hereinbefore and hereinafter referred .to. Extending upwardly from the left hand side of the frame or base 10, as viewed in Figure 9, is a pedestal or support l2 upon the upper surface of which is mounted a suitable source of power, shown in the drawings in the form of ,an electric motor M. The drive shaft of the motor is supplied with a chain drive 16 which extends downwardly and engages a sprocket l8 (Figure 9).

Referring to Figure 11, it will be observed that the sprocket I8 is enclosed within a housing 20 disposed adjacent to or even "made a part of the pedestal I2,. it being understood that a portion of the housing 20 is cut away to permit the chain Hi to pass therethrough. Continuing to refer to Figure 11, it will be seen that the sprocket or gear I8 has formed integrally therewith a second gear '22 which in turn drives a chain indicated in mounted within a casting 58 which forms a major part of the swinging head. The tube support or bearing is indicated by the reference numeral 42 and includes a cylindrical bearing portion 60 disposed closely adjacent to the roll 50. The tube support or bearing 42 is rotated in order to impart rotation to the tube as its contour is being changed, and to this end the annular support is mounted within ball bearings 62 which in turn are disposed within a stationary casting 64.

In operation, the tube extends comparatively loosely through the rotary bearing in the manner illustrated in dotted lines in Figure 11 and there might be a tendency for slippage to develop between the tube and the bearing were it not for the fact that the pressure exerted by the ring-roll on the surface of the tube causes the latter to be held in firm frictional engagement with the bearing in such a manner that the tube and bearing rotate uniformly although the tube is simultaneously moved lengthwise through the hearing. In this same connection it will be appreciated that very thin wall tubing would hardly be suitable for reduction on the machine in view of its tendency to collapse. Primarily the machine is designed and intended to operate on tubing having walls of moderate or substantial thickness by continuously and progressively working the tube circumferentially from end to end.

In the operation of the mechanism which has just been described, both the ring-roll and the tube support or bearing 60 are rotated and it is desirable to maintain the speed of rotation of these two parts in such a manner that relative slippage of the tube and the rol1 or the tube and the bearing will be avoided. Thus, let it be assumed that the bearing support 60 rotates at a ,uniform speed. Each time that the ring-roll bevel gear 28 which is keyed to the sleeve 32 by means of a suitable pin 34. Similarly, disposed to the left of the differential pinions 26, as i1- lustrated in Figure 11, is a combined spur and bevel gear 36, the beveled portion 38 of which is arranged to mesh with the teeth formed on the differential pinions 26 and the spur portion 40 of be observed that the opposite extremities of the jack shaft are mounted in ball bearings 52 and 54 in the customary manner.

At'this point will be reviewed briefly the manner in which the ring-roll and the tube support,

descends into the tube to alter the surface contour thereof it will be necessary to change the relative speed of rotation of the roll in order to prevent slippage of the roll on the tube. It is for the purpose of accommodating and permitting this variation in speed between the roll and the bearing that the differential gearing is provided.

It has already been pointed out that the rin roll'is free to move bodily relatively to the axis of the tube in order to engage the tube and change the contour thereof in the manner illus-, trated in such figures as 3 to 6, inclusive, and 12 to 18, inclusive, and to this end the roll is mounted within a swinging head or housing which has heretofore been referred to. This housing, as already pointed out, includes the member 56 which is mounted, as shown in Figure 11, to pivot about the jack shaft 30 at the point 66. Thus, it will 7 be seen from an inspection of this figure that the swinging head assumes the shape of a flat annular member which encloses the ball bearin 56, the driven member 46 and the ring-roll 50. By virtue of this form of construction the gear teeth formed on the driven member 46 will at all times remain in firm driving engagement with the teeth on the gear 44 because both the latter and .the former are mounted upon the same jack shaft 30, and as the swinging head moves about the shaft the distance between the gear teeth 40 and the shaft at all times remains the same.

Movement of the swinging head about the jack shaft 30 will be somewhat limited owing to the fact that changes. in the profile or contour of the tubes will be small in dimension as compared to the general dimensions of the machine, and thus it will be recognized that the feature of imparting movement to the swinging head and to the ring-roll which is carried thereby can be accomplished by imparting slight, predetermined movement to the swinging head in a vertical or near vertical plane. For the purpose of raising and lowering the swinging head in order to permit the ring-roll to descend or ascend, the machine is provided with a mechanism which will now be described. Located on the frame I and extending lengthwise thereof is a templet or cam track I0, the upper contour of which controls the contour that is imparted to the finished tube. A roller or guide I2 is arranged to ride over the upper cam surface or path and imparts movement to a valve arm 14, which valve in turn controls the admission of fluid to a hydraulic cylinder 10.

The swinging head is provided with a bracket arm 18 which carries an adjusting set screw 00. The swinging arm is arranged to move upwardly or downwardly relatively to a frame member 82 which is positioned beneath the adjustable set screw 00 and in turn carries the valve member 04 heretofore referred to. The purpose of this arrangement is to permit initial adjustment of the ring-roll prior to the commencement of a reducing or contour-changing operation. Thus, if a tube is inserted in the machine which is slightly smaller on outer diameter than the previous tube, the adjusting screw 80 may be called into use. For example, if the machine has been operating on a tube having a four-inch outer diameter and it is desired to use the machine in the next operation for reducing a tube having a diameter of three inches, the vertical position of the swinging head will be lowered one-half inch-to compensate for the difference in diameters. This adjustment is accomplished by means of the set screw or adjusting screw 80. Once, however, the position of the roll has been properly adjusted with respect to the tube the adjusting screw plays no further part in, the operation of the machine until some future change in requirements demands it, and the weight of the swinging head causes the ad- 'justing screw to maintain firm engagement with the top of the member 82, in which condition the arm 18, the adjusting screw 00 and the member 02 swing together as an integral or unitary memher. As heretofore pointed out, motion is imparted to the member 82 by means of the hydraulic member I6, the movement of the plunger of which is in turn controlled by variations occurring in the surface of the templet 10 which moves backward or forward beneath the stationary roll 12.

A guideway 86 is attached to the machine frame, as shown in Figures 7 and 9, and is adapted slidingly to receive the templet and maintain it in an upright position during the operation of the machine. The extremity of the templet located to the left of the machine, as illustrated in Figure 7, is free and the extremity located to the right, as shown in that figure, is secured at 88 to a movable carriage 00. The purpose of the carriage generally is to feed the tube during the reducing or contour-changing operation, and it will be understood that the elongated templet or cam I0 travels with the carriage and controls the position of the ring-roll during the time the tube is being fed therethrough. In order to bring about the feeding motion of the traveling carriage 00 a chain member 24, previously-.mentioned, is driven from the gear 22, shown in Figure 11, through a suitable opening in the housing 20. This chain in turn engages and drives a gear 92 fixed upon a jack shaft 04, as shown in Figures 1 and 9. Upon the jack shaft 84, as

shown in Figure 1, is mounted a pinion gear 00 which engages with and drives a second gear 00 rigidly secured to the extremity of a worm shaft I00. A longitudinal groove I02 is cut in the worm shaft I00 and receives an interlocking projection formed on a worm gear I04, shown in Figure 1. The worm gear I04 is accordingly free to move lengthwise on the shaft I00 but is held against relative rotation with respect thereto.

Turning to Figure '7 it will be observed that the same shaft I00, groove or slot I02 and worm I04 are incorporated in the arrangement therein illustrated for the purpose of imparting motion to the carriage 00 in the manner that will now be described. As shown both in Figures 1 and 7, the worm has driving engagement with a gear I06 mounted on a movable shaft I08, which is shown in Figure 10 as well as Figures 1 and 7. The shaft I08 is one of two parallel shafts, the other being indicated by the reference numeral H0, and each of these shafts carries at its outer opposite extremities gear wheels I I2, I I4 which have driving engagement with a stationary rack II6 mounted on the frame I0.

A clutch mechanism is included in the machine for the purpose of reversing the direction of travel of the carriage and this mechanism is illustrated in Figure 10. As therein shown, a plurality of interlocking members, which may be referred to as clutch elements H8, I20, are. secured to the shafts I08, IIO, respectively, and although adapted to have sliding movement thereon are held against rotary motion with respect thereto.

, Motion can be imparted to either of these clutch elements 0, I20 alternately by means of move ment imparted to an operating arm I22. Thus, if the arm I22 is moved to the right from the position illustrated in-Figure 10,.the clutch element I20 moves in the direction of what may be referred to as its engaging position, and simultaneously the other clutch element II8 moves away from its engaging position. By the same token, if the operating member is moved to the left, the clutch element II8 moves toward its engaging position and the member I20 moves toward its disengaging position. Mounted upon the shafts I08 and H0 and arranged to cooperate with the clutch elements H8 and I20 are a plurality of gears I24, I20 which are arranged to rotate freely upon the respective shafts. However, the gears are provided with hub portions I28, -I30 which constitute clutch elements adapted to cooperate with the elements H8 and I20. Thus, if the element I20 is moved into engagement with the element I30 the gear I26 thereupon becomes pinned to the shaft IIO, causing the carriage to move in one direction, and alternately, if the element H8 is engaged with the element I28 the gear I24 is clutched to the shaft I08, causing the gears to.travel in the reverse direction. This reversal of direction is brought about, it will be understood, by reason of the fact that the worm drives the gear I06, which in turn drives the gear I24 and causes travel in one direction, whereas if the gear:,I24 is released from the shaft I28 it serves merely as a reversing gear and drivesthe gear m, which in that event will be clutched to the shaft 0. Motion will be imparted to the operating lever I22 either by means of stops mounted on the frame of the machine or by other suitable means which may be left to the choice of the operator. Similarly, it could be a hand operation if desired. Also, it will be understood that with the operating arm I22 in neutral position the carriage remains at rest and does not travel in either direction. I

From so much of the description as has been given will be understood the manner in which the various parts are driven and likewise the fact that as the tube is fed through the rotary ringroll 50 displacement of the roll relatively to the tube is brought about by means of the templet 10, thereby imparting the desired configuration to the tube. Thus, if the slope of the templet or cam surface 10 should be slowly sloping the ring would descend gradually and would be inclined to impart a taper to the tube. n the other hand, if the configuration of the templet should be, let us say, in the nature of a scallop, the tendency of the roll termed a corrugated effect. It will be understood that there is a conjoint motion or. action between the plug I60, and the head I60 is then moved into position and drawn tightly home by means of the draw bolts I62. This action causes the tapered surfaces to cooperate with one another and to drive the split sleeve into firm engagement with the tube. It will be understood that .various forms and types of clamping devices can be employed to carry outthefunction performed by the type i1lustrated,,and of course it will be realized that the invention is not concerned with details of this type.

In some types of operations it will not be necessary to use an arbor or a mandrel within the hollow interior of 'the tube to cooperate in effecting the reducing operation, and when no arbor The mandrel is maintained within a bearing'race the ring-roll which moves withina vertical plane and the tube which is moved or fed horizontally.

In other words, unless the tube-is in motion, causing movement to be imparted to the cam roll 12, there would be no operation because the ring-roll would in that event occupy a stationary position, and it is therefore through the conjoint action of the tube and roll motions that the. beneficial features of the invention are largely obtained.

\ Turning now to what may be regarded as a few more detailed features of the invention, the attention of the reader is invited, first, to Figure 2, in which is illustrated a manner of holdinglthe extremity of the tube during a reducing operation without causing any waste to be formed and without injuring the tube in any way. As therein illustrated, the carriage 90 is provided at its upper extremity with a shaft I40 having a headed extremity I42 which engages and maintains in firm engagement with the carriage-90 a ball bearing I 44. A casing I46 surrounds the ball bearing and is free to rotatev thereon. An annular plate I 48 is associated with the casing I46 and is held in position by means of bolts I50. In operation the easing I 46 is freeto rotate on the ball bearing I44, which in turn is supported by means of the shaft I40 extending outwardly from the carriage 90. A plug I50 has screw threaded engagement I52 with an opening formed in thecasing I46 and the outer diameter of the plug corresponds approximately to the inner diameter of the tube being operated upon. This plug prevents the tube from collapsing and affords a solid and secure inner support. Arranged to cooperate with the plug in gripping the tube and maintaining it in firm supporting position is an annular split sleeve I54 arranged to surround the tube and the plug I50 and the ring is provided with a tapering outer surface I 56 which has cooperating engagement with a reversely tapered surface I58 formed on a head I60. Draw bolts I62 serve to maintain the head I60 and the casing I46 in assembled relationship. Thus, it will be seen that in assembling this device the tube is first inserted over the plug I50, whereupon the split sleeve I56 is moved into position adjacent the extremity of the tube and I14 by means of a lock nut I16 and the bearing race in tum is disposed within a casing I18 and maintained therein by means of a closure plate I80. The parts just referred to comprise a chuck for supporting the mandrel, and as shown, the chuck is mounted upon the screw threaded extremity of a shaft I82 extending outwardly from the piston of a hydraulic cylinder I84. In the employment of the machine for certain purposes it will be desirable to impart to the mandrel a short reciprocating action, and it is for'this reason that the hydraulic cylinder I84 is provided. Connections I86 and I88 of the conventional type extend to the cylinder and the admission of fluid through these connections is controlled by means of a second templet I90 disposed adjacent the templet 10 and provided with a cam roller I92 and a control valve I94, the movement of which is controlled by the movement of the roller over the templet I90, and in turn controls the admission of fluid to the hydraulic cylinder I84. In this manner and by employment of this mechanism any desired range or type of motion may be imparted to the mandrel I10.

In the operation of the machine the feeding action can be accomplished in one of two ways.

In the first place, the tube can be pulled through the machine, and in the second place, it can be pushed through the machine. Thus, as illustrated in Figure 1, the tube is being pulled, and as I shown in Figure 7 it is being pushed. In order to effect the pushing of the tube through the roll a tube-holding device of the type shown in Figure 8 may be employed. As therein illustrated, a hollow sleeve I96 is surmounted upon the carriage 90 and is provided with an annular flange through the carriage and through the tube in the manner shown above in Figure 7.

So much for the description of the machine itself. From what has been given above it is be lieved that the construction and operation of the machine will be apparent, although it is to be realized that various changes in design and details of'construction and arrangement of parts may be made without departing from the scope of the invention as outlined herein and set forth in the appended claims.

Turning now to the various types of operations that may be performed on the machine, in Figure 3 will be seen a tube having a straight taper imparted thereto along a line indicated by the reference numeral 206 and a cylinder formed at the point 208. It will be understood that the dotted line 2| ll indicates merely apossible line of severance in a completed tube in order to divide a tube that has been processed on the machine into a plurality of smaller sections.

In Figure 4 shoulders are located at the points 212 and 2H and the length of tubing in between these shoulders has been convexed as indicated by the reference numeral 2l6. In Figure 5 the shoulders H2 and 2 are again present and the metal in between them has been shaped to form a reduced cylinder which, as hereinafter explained, may be of the same, or less, or even greater wall thickness than that of the original tube.

In Figure 6 the tube has been concaved, as indicated by the reference numeral MB. In all of these the dotted line indicates merely a line of severance and not a complete length of tubing.

A single length of tubing could be convexed or.

concaved or tapered from one end to another, but ordinarily it will be desirable to make several tapered members or sections out of a single tube,

and the bearing 60 is rotating at approximately the same speed, .or at least at such a. Sp ed as will prevent any slippage of the ring-roll on the surface of the tube as the latter is engaged by the roll. With the parts operating in this manner the tube may be pushed to the left, as shown,

' and if the position of the ring-roll is permitted to remain unchanged the diameter of the tube will be reduced in the manner shown 'in Figure 13. During this reducing operation there may be a slight increase in wall-thickness, but it will be negligible for all practical purposes. If the ringroll 50 is permitted to ascend during the pushing or feeding of the tube to the left the reducing operation willassume the form shown in Figure 14 in which a straight taper has been imparted to the tube along the line 220. In this operation the tube is initially reduced at the extremity in the manner illustrated in Figure 13 and then as the tube is fed on through the roll the latter is permitted to ascend, thereby uniformly decreasing the amount of the, reducing operation and providing the taper that is illustrated.

In Figure 16 there is diagrammatically show a tube being pulled through the roll and the bearing ill. In Figure 17 the tube is being pulled process are capable alsoof reducing the wall thickness of tubing and to this end an arbor is employed in the manner shown in Figures 15 and 18. As therein shown, the roll is placed in a position in which the distance between the working surface of the roll and the arbor represents the thickness of the tube that it is desired to produce, which thickness, of course, will customarily be less than the thickness 'of the original tube. With the arbor and the ring-roll in this position the tube may be fed forward and as the roll rotates and the tube rotates the entire tube will pass through the reduced opening, thereby effecting a reduction in the wall thickness. This type of operation is illustrated in Figure 15. It has, however, been found possible with this machine, and the machine was designed with the thought in mind, of simultaneously tapering and reducing the wall thickness of tubular products. This type of operation, which is one of the most difficult, is shown in Figure 18. As therein shown, the arbor is employed in order to effect the operation of reducing the wall thickness of tubing and the roll is permitted to descend in order to taper the tube as it moves through the roll. However, it will be appreciated that if the arbor is stationary and if the roll descends, the distance between the roll and thearbor will continue to decrease until the tube is fractured or ruptured. To prevent this defect the arbor is moved rearwardly as the roll descends in order that the distance between the two will remain uniform. For the purpose of moving the arbor relatively to the ring-roll the machine is provided with the hydraulic cylinder I84 hereinbefore described.

The machine herein described is capable of tapering tubes without the use of an arbor, although it is contemplated that in certain circumstances it may be desirable to employ a conventional tapered arbor down the surface of which the metal may be worked by means 'of the circumferential reducing pressure applied by the ring-roll. Also, as referred to herein and in the claims appended hereto, the term "reducing as employed in reference to metal tubes is generic .and includes any operation which changes the contour or profile of the tube or the wall thickness thereof. In the first instance the outer diameter of the tube is being reduced in some localities, and in the second instance the thickness of the tubing is being reduced.

flciently slow to prevent appreciable spiral groov-' ing of the tube by reason of the fact that each portion of the tube is repeatedly subjected during rotation to the pressure of the forming tool.

but the ring-roll 50 has been permitted to detour of the tube. However, the machine and Also it will be understood that although the tube may be moved or fed lengthwise it is held against any accidental bodily displacement which might occur by reason of the action of the tool upon the shoulder or deforming areas of the tube. Although as illustrated herein the tool is held against bodily displacement and the tube is moved longitudinally, it is to be appreciated that the tool might be moved lengthwise .of the Having thus described the invention, what I claim as new and desire to secure by Letters Patent of the United States is:

1.1In a tube reducing machine 'of the character described, the combination of a reducing tool in the form of a continuous ring roll having an inner diameter at least as great as the exterior diameter of the tube to be reduced, an exterior tube support having an interior diameter of a size to closely surround theunreduced portion of the tube and afford an exterior reinforcing bearing therefor, said tube support being located immediately adjacent the acting face of the ring roll, a mounting for the ring roll adapted to permit movements of the ring roll in a substantially radial direction toward and from the axis of the tube being reduced and across the adjacent face of the tube support, means for imparting relative longitudinal movement between the tube and the ring roll with its adjacent tube support, means for automatically imparting variable radial movements to the ring roll mounting and the ring roll to radially adjust the distance of its contacting surface from the axis of the tube in imparting varying degrees of reduction to the tube, and means whereby relative rotation is maintained between the tube and the contacting portion of the ring roll applying a reducing pressure thereon to cause the metal of.

the tube wall to flow inwardly adjacent the external tube support in the evolution of a low pitched spirally extending shoulder, the rate of rotation being relatively rapid in ratio to the rate of relative longitudinal movement to prevent appreciable spiral grooving of the tube.

2. In a tube reducing machine of the character described, the combination of a reducing tool in the form of a continuous ring roll having an inner diameter at least as great as the exterior I diameter of the tube to be reduced, an exterior tube support having an interior diameter of a size to closely surround the unreduced portion of the tube and afford an exterior. reinforcing bearing therefor, said tube support being located immediately adjacent the acting face of the ring roll, a mounting for the ring roll adapted to permit movements of the ring roll in a substantially radial direction toward and from the axis of the tube being reduced and across the adjacent face of the tube support, means for imparting relative longitudinal movement between the tube and the ring roll with its adjacent tube support, means for automatically imparting variable radial movements to the ring roll mounting and the ring roll to radially adjust the distance of its contacting surface from the axis of the tube in imparting varying degrees of reduction to the with to cause the metal of the tube wall to flow inwardly adjacent the external tube support in the evolution of a low pitchedspirally extending shoulder, the rate of rotation being relatively rapid in ratio to the rate of relative longitudinal movement toprevent appreciable spiral grooving of the tube.

3. In a tube reducing machine of the character described, the combination of a reducing I tool in the form of a continuous ring roll having an inner diameter at least as great as the exterior diameter of the tube to be reduced, an exterior tube support having an interior diameter of a size to closely surround the unreduced portion of the tube and afford an exterior reinforcing bearing therefor, said tube support being located immediately adjacent the acting face of the ring roll, a mounting for the ring roll adapted topermit movements of the ring roll in a substantially radial direction toward and from the axis of the tube being reduced and across the adjacent face of the tube support, means for imparting relative longitudinal movement between the tube and thering roll with its adjacent tube support,

means for automatically imparting variable radial movements to the ring roll mounting and the ring roll to radially adjust the distance of its contacting surface from the axis of the tube in imparting varying degrees of reduction to the tube, and power actuated means for rotating the tube support and the tube enclosed thereby while allowing relative longitudinal movement between the tube support and the tube to thereby establish a rotative relation between the tube wall and the point of contact of the ring roll therewith to cause the metal of the tube wall to flow inwardly adjacent the external tube support in the evolution of a low pitched spirally extending shoulder, the rate of rotation being relatively rapid in ratio to the rate of relative longitudinal movement to prevent appreciable spiral grooving of the tube, and power actuated means for rotating the ring roll in the same direction as the rotation of the tube.

4. In a tube reducing machine of the character described, the combination of a reducing tool in the form of a continuous ring roll having an inner diameter at least as great as the exterior diameter of the tube to be reduced, an exterior tube support having an interior diameter of a size to closely surround the unreduced portion of the tube and afford an exterior reinforcingbearing therefor, said tube support being located immediately adjacent the acting face of the ring roll, a mounting for the ring roll adapted to permit movements of the ring roll in a substantially radial direction toward and from the axis of the tube being reduced and across the adjacent face of the tube support, meanfsjfor, imparting relative longitudinal movement between the tube and the ring roll with its adjacent tube support, means for automatically imparting variable radial movements to the ring roll mounting and the ring roll to radially adjust the distance of its contacting'surface from the axis of the tube in imparting varying degrees of reduction to the tube, and power actuated means for rotating the tube support and the tube enclosed thereby while allowing relative longitudinal movement between the tube support and the tube to thereby establish a rotative relation between the tube wall and the point of contact of the ring roll therewith to cause the metal of the tube wall to flow inwardly adjacent the external tube support in the evolution of a low pitched spirally extending shoulder, the rate of rotation being relatively rapid in ratio to the rate of relative longitudinal movement to prevent appreciable spiral grooving of the tube, and power actuated means for rotating the ring roll in the same direction as the rotation of the tube, said means including differential transmission elements in the power train to the ring roll and the tube support to maintain substantial equality in the surface speeds of the tube and ring roll at the point of contact irrespective of radial adjustments of the ring roll.

5. In a tube reducing machine of the character described, the combination of a reducing tool in the form of a continuous ring roll having an inner diameter at least as great as the exterior diameter of the tube to be reduced, an exterior tube support having an interior diameter of a size to closely surround the unreduced portion of the tube and afford an exterior reinforcing bearing therefor, said tube support being located immediately adjacent the acting race or the ring roll, a pivoted mounting for the ring roll adapted to permit oscillatory movements of the ring roll in a substantially radial direction toward and from the axis of the tube being reduced and across the adjacent face of the tube support, means for imparting relative longitudinal movement between the tube and the ring roll with its adjacent tube support, a template having a configuration conformable to the intended configuration of the tube and connections relatively movable with respect to the template for imparting variable radial movements to the ring roll mounting and the ring roll to radially adjust the distance of its contacting surface from the axis of the tube in imparting a predetermined configuration in the reduction of the tube, and means whereby relative rotation is maintained between the tube and the contacting portions of the ring roll applying a reducing pressure thereon to cause the metal of the tube wall to flow inwardly adjacent the external tube support in the.

evolution of a low pitched spirally extending shoulder, the rate of rotation being relatively rapid in ratio to the rate of relative longitudinal movement to prevent appreciable spiral grooving of the tube.

WALTER E. AMBERG 

